1. Field of the Invention
The invention is directed to a hydraulic actuating drive, especially for a clutch.
2. Description of the Prior Art
A hydraulic actuating drive is known, for example, from German reference DE 42 37 853 A1, which comprises a hydraulic pump driven by an electric motor. The hydraulic pump delivers hydraulic fluid from a reservoir to a pressure accumulator via a check valve. A pressure sensor is associated with the pressure accumulator and is connected with the supply tank, for safety reasons, by a pressure overload valve which limits the maximum pressure in the pressure accumulator. By means of a control valve which is connected with the pressure accumulator, on the one hand, and with an actuating cylinder, on the other hand, and is switched by means of a control unit, the actuating cylinder is acted upon by pressure. The actuating cylinder is connected with a slave cylinder associated with the clutch via a hydraulic line.